Improvement in smoke-consuming furnaces



J. G. HUNT. Sm ke-Consuming Furnaoe.

Patentd Dec. 23,1879.

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m w m Inventor.

` N-PETERS. FHOTO-LTHOGRAPHER. WASQVHNGTDN, D C,

U ITED STATES PATENT OFFICE. i

JAMES Gr. HUNT, OF CINCINNATI, OHIO.

IMPROVEMENT IN SMOKE-CONSUMING FURNACES.

Specification forming part of Letters Patent No. 222.824. dated December23, 1879; application filed August 29, 1879. V

To all whom it may concm:

Be it known that I, JAMEs Gr. HUNT, of the city of Cincinnati, county ofHamilton, and

State of Ohio, have invented certain new and useful Improvements inSmoke- Gonsuming Furnaces, of which the following is a specification. i

My improvement is applicable to the various descriptions of app-aratusfor burning fuel, but is more particularly designed to be used inconnection with apparatus for generating stearn; and my improvementshave for their object the consumption of the smoke generated by thecombustion of fuel in said apparatus.

The first feature of my invetion consists in such an arrangement of thegrate-bars of the furnace and of the ash-pit as that the gratebars shallbe substantially on a level With each other, and the ash-pit shall bedivided into two chamloers, the rear one of which shall be capable ofsupplying the fire on the grate above said chamber with fresh air of adesired temperature, the air thus passing up through the grate over thesaid rear or second chamber acting, in connection with the bed of coalsthereupon, to consume the smoke generated from the greener fuelburningupon the grate over the front chamber.

The second feature of my invention consists in adding to a furnaceconstructed according to the first part of my invention, and behind therear brid ge-wall a plate or grating, located in substantially the samehorizontal plane as the grate, and provided with perforations to admitof the passage from beneath of air through the same to the unconsumedsmoke and gases passing over the bridge-wall, for the purpose ofconsuning the said smoke and gases.

The third feature of my invention consists in combining with a twinfurnace-that is, a furnace having duplicate ch ambers, each chamberprovided with one orboth of the aforementioned features of myinvention--an opening located near the forward end of the furnace andconnectin g the same, and also in providin g suitable dampers at thelast bridge-wall of said furnaces, in such a manner that the smoke andunconsumed gases from either furnace shall be compelled to pass throughthe other furnace at will, and in their passage over the fire of thelatter shall be consuned.

The fourth feature of my invention consists in the application to eitheror any of the aforementioned features of my invention of a useful devicefor introducin g air or steam, or both mixed together, the introductionof said gases being on opposite sides, and near the rear part of thefurnace, for the purpose of increasing the draft of the fire, and alsoof aiding in consuming the smoke.

While this dcvicc naywith advantage he located at many points in thefurnace, the location hereinafter specified is a very advantageous one,and this location is another feature of my invention.

For convenience of illustration, I will describe a twin furnace employedto heat a steamboilcr, and provided with my improvements.

In the accompanyin g drawings, making part of this specification, Figurel is a perspective view of a furnace and boilcr enbodying my invention.Fig. 2 is a horizontal sectional View of same, taken on a level with thecenter of the boilcr, the boiler being removed to show the partsbeneath. Fig. 3 is a sectional View taken at the line x x of Fig. 2. Fg.4 is a sectional view taken at the liney y, Fig. 2, and looking towardthe rear, the boiler also being shown in position. Fig. 5 is a devicefor closing the orifice Q.

AA' are the furnaces, over which is a steanboiler, B, providedlwith areturn-fine, b, the rear end of which is suitably connected with thefurnace, and the forward end to the chimney (J. Each furnace is providedwith a set, D, of horizontal grate-bars, supported in the usual mannerin front, and at the rear by the partition or bridge wall E, whichlatter supports the forward end of a second set, F, of gratin g,supported at the rear by a brid ge-wall, g. These two sets of gratcs maybe' one; but for the convenience of setting, wear, and repair, they arepreferably made as described. Directly behind the grate a damper, H, isso arranged as to be capable of shutting ofi' the space under the rearportion of the boiler from the furnace.

This dam per may be connected and operated in any suitable manner, butis preferably, as here, hinged at its upper edge, and operated 222.824&

by a shaft, d, terminating in a crank-handle, e, the latter beinglocated outside of the furnace, and within reach of the stoker oreugineer.

At the rear of the damper His the perfo- 'rated plate or grating I,suit-ably supported, as

shown. This plate is preferably somewhat inclined downward from front torear, as shown, so that ashes or dust cannot accumulate 011 it to suchan exteut as to cover over the holes.

The ash-pit D', under grate D, and the ashpit F', under grate F, and theash-pit I', under plate or grating 1, are each provided with a suitabledoor, f, for the removal of the ashes, and for permitting, when desired,a very free fiow of air through the same.

The partition-walls E and Gr are also preferably connected with eachother by means of an opening or openings, J, as shown, closed byappropriate dampers. The ash-pit I', in addition to the dampers in theash-pit door, may also be provided with one or more orit'ces,f', locatedin its side and regulated by appropriate dampers.

The two furnaces are entirely separated by a partition-wall, K, exceptat their front portion above the grate and below the boiler, where anopening, L, connects them. Each of these furnaces is fed through theusual door M, suitably located at the front, as shown, or side of thefurnace. At the inner side of the outer Wall of each furnace, and nearthe junclion of the latter with the boiler, is located a perforateddischarge device, N, fed through a pipe, P, which is preferublycontinued to the front of the furnace, and terminates in a bell-shapednouth, Q, outside the wall, into which mouth enters a steain-pipe, R,connected with the steam-space of the boiler. This pipe E is some- 'whatsmaller than pipe P, for the reasons hereinafter mentioned, and does notextend quite to the end of P.

My improvements operate as follows:

Where but one furnace is employed, or the furnaces are operatedseparate] y, the operation of the same is as follows: A fire of greencoal being kindled and allowed to burn for a short time, theincandescent coals are pushed back onto grate F and more green fuelsupplied by grate D. The ordinary combustion takes place on grate D,which is supplied with air from ashpit D', derived through ash-pit doorA or any other suitable source. The gases and smoke generated by theignition of the green fuel pass over the incandescent coals upon grateF, and, by means of a fresh supply of air com-v ing up through thelatter grate from ashpit F' and supplying fresh oxygen to the fire atthis point, the conbustion is increased and intensiied and the smoke andgases are i gnited. Any residue of gases and smoke (if it should happenthat any of same should not be consuned over the grate F) passing off ofgrate F are supplied in their passage over plate or gratin g I withfresh air (oxygen from the pit l') through the orifces in said plate I,and are thereby oonsumed.

The fresh air from without the furnace to be supplied to the grates D,F, or I may be introduced to the same in any suitable manner, but ispreferably introduced as follows: The air for grate. F may be suppliedthrough the door of pit F', or through orifices in the side wall abovethe door, or from ash-pits D' or I' through orifices J in thepartition-walls, as desired; and the air for grate I may be supplicdthrough the door of ash-pit I', or through orifices in the side of thefurnace above the same, as g, or through the orifices J from ashpit D'or ash-pit F'.

YVhere the air to be supplied to grate F or I is needed in a warmcondition, it is preferable to have it pass beneath grate D or F, orboth, for grate l, and beneath grate D or I for F.

The operation of device N P Q R is as follows: The passage of steamthrough pipe R being controlled by faucet IL, the pipe E is closedwhenever it appears desirable to introduce air alone to the fire throughthe device Q P R. The draft of the fire draws air through opening Q; atthe sides of pipe R, and through pipe P, and through the orifices indevice N, and the air thus introduced increases the combustion of thefuel, and also of the smoke and gases generated therefrom; or, should itbe desirable to introduce steam alone, the orificc Q may be closed bysome appropriate device around the pipe P, thus not allowing air toenter. I have found, however, that a mixture of steam and air introducedto the furnace by device N contributes much more toward a perfectcombustion of the fuel, smoke, and gases, 850., than either air or steamalone. To thus introduce such a mixture by faucet h, I open pipe R, andthus allow the steam to pass through pipe R and into pipe P, whece itpasses (by its own projcctile impulsion and by the draft of thefurnacefire creating a suction through pipe P toward N) through pipe P,at which point it becomes mixed with air drawn in through inlet Q, andin this mixed condition' the air and stean pass through the device Ninnumerous jets to increase the com bustion.

The draft of the furnaces is to be regulated by suitable dampers-as, forexample, damper H can be used for this purpose.

The unconsumable invisible gases and heated air pass through the fiue ofthe boiler from rear to front, and thence into chimney O, in the usualnianner.

When it becomes desirable to employ the furnaces together, by means ofopening L, the green fire is first made in one of the furnacessay A-anddamper H in furnace A being closed, and damper H in furnace A' beingopened, till the fire has become a.bed of live coals.

The operation of this furnace in consuming the smoke is carried on bymeans of grates F and I, as heretofore specified, the heated air andunconsumable products of combustion passing through the open damper H infurnace A, and thence through the boiler into the chimney. I then makeafire of green coals in furnace A', and the unconsumed smoke, 850.,generated from said green fire in furnace A pass from saidfurnace'through opening L into furnace A, and over the bed of coals inthe latter, the air 'supplied by grates F- and I as sisting in thecombustiou of said smoke and gases, and the air and steam-enteringthrough device N of furnace A assisting in the result. The steam and airas they enter the furnace through the device Nstrike against the closeddaniper H, causing an eddy or whirl, thus causing the more completemiXture of the various gases. It then takes a course toward the openingL, causing a greatincrease in the draft.

Steam being iutroduced through the device N of the opposite side of thefurnace does not meet with the resistance of the damper H, as thisdamper is open. This steam, therefore, passee through the open damper,also giving a great increase to the draft.

The perforations in device N are 1'ret`erably directed at a backward angle to direct the steam and air toward the damper H. The nonconsumablegases then pass through damper H in furnace A, and through the boiler,&c., as specified.

When the fire in fu-nace A is to bc repleislied the damperH of the sameis to be closed,

means at'oresaid, and the residue thereof pass through damper H infurnaee A', and through the boiler, as specified. This operation isrepeated as often as fresh fuel is added, care being taken so to operatethe dampers as to cause the smoke and gases from the green coal in theone chamber to pass through the other furnace, and thus over the livecoals therein.

What I claim as new and of my invention, and desire to secure by LettersPatent, is-

1. The combination of the grates D and F, substantially on the samelevel, and the perforated plate or grating I, and the chambers D F', andI', immediately succeeding each other, the perforated plate or grating Ibeing immediately over the chamber I', substantially as and for thepurposes specified.

2. The combination of the grates D and F, substantially on the samelevel, and the perforated plate or grating I, Situated above the chamberI', and the chanbers D', F', and I' immediately succeeding each other,and ashdoors and orifices J, said orifices being in bridge-wall Gr,substantially as and for the purposes specified.

3. The combination of grates D F and plate I andchanbers D' F' I' anddamper H, placed between grate F and plate I, substantially as and forthe purposes specified.

4. The combination of the grates D F, placed substantially on the samelevel, and the chambers D' and F and the damper H, placed directly afterthe grate F and between the boiler and bridge-wall, substantially as andfor the purposes specified.

5. The twin furnaces A and A', each provided with grates D, F, and I,and chanbers D', F', and l', and dampers H, located between grates F andI, said furnaces being connected by opening L, substantially as and forthe purposes specified;

(i. The twin furnaces A and A', each provided with grates D and F, andchambers D' and F', and dampers H, located immediately above bridge-wallG, all in combination with opening L, substantially as and for thepurposes specified.

7. The combinatiou of the perforated dischargevessel N and pipe P,located substantially as described, and the grates D and F and chambersD' F', substantially as and tor the purposes specified.

S. The conbinaton of the discharging device N P, located substautiallyas described, and the grates D, F, and l, and chambers D', F', and I',substantially as and for the purposes specified.

9. In a twin furnace, the combinatiou of the discharging device N P, andthe grates D and F and I, and chambers D', F', and I',`aud opening L,and dampers H, located between grates F and I, substautally as and forthe purposes specified.

JAMES GEORGE HUNT.

Attest:

E. H. FOSTER, JNO. W. STREHLL

